I did that on a weekend my first year teaching. I was working in my room on a Sunday and went out to my car to get a jacket. I was literally in the middle of eating lunch, but I hadn't realized they turned the heat way down on weekends and was so cold I got up in the middle of eating to go get the jacket. My purse, cell phone, laptop, and half eaten lunch were sitting on my desk along with my key to the school, which was on it's own keychain. As soon as I walked out I realized I needed to prop the door and tried to grab it but it was too late. Luckily I had my car/apartment keys in my hand...I ended up just having to drive home and wait for school until the next day. I honestly don't know what I would have done had I walked out without my car/apartment keys in my hand since I didn't have a phone either..so it could have been worse I guess.
I agree that it was right to wait. I would only take drastic measures if it were a holiday break or something or something happened where I absolutely had to have something in the purse that day.